The research program will be focused on problems of biological effects of environmental alterations in relation to human health and disease. The environmental agents include those known or suspected of disease potential; but many are neither known nor suspected. Therefore, an important part of our responsibilities will be to undertake studies for their identification. Emphasis will be on major human diseases, as environmental cancer and environmental lung disease. Priorities will be devoted to problems that affect very large numbers of people. The research program will be very much concerned with mechanisms, ranging from the cellular level to the conceptual level, as in the delineation of multiple factor effects in environmental disease. Five major program areas are of interest to us; multiple factor etiology as noted, environmental cancer, effects of long-term, low-level exposure to environmental agents, including those associated with asbestos, and the biological effects of ultramicroscopic inorganic particles. In approaching these problems, we intend to adhere to several methodological perspectives. First, since we are concerned with human disease, our studies will investigate environmental effects in large populations. Inevitably, this involves epidemiological emphasis. Among the populations investigated will be occupational groups. On the other side of the equation, we intend to define dose-disease response relationships, indicating that environmental evaluation will be equally important in our research. The interaction of the biological and physical sciences has been a pervading element in our research, and will continue so in this program.